The present invention relates to a brake fluid control apparatus for vehicles, which is used for brake fluid pressure control such as antilock brake control and traction control.
Such kind of brake fluid control apparatus generally has following construction for reducing size, weight and cost. Namely, an electric motor for actuating a pump is mounted on one side of a housing in which devices for fluid pressure control such as the pump and electromagnetic valves are accommodated and passages are formed. Further, on the other side of the housing, an electronic control box provided with a connector for connecting a control circuit board to a battery is mounted.
In such construction, the electric motor mounted on one side of the housing and the electronic control box mounted on the other side of the housing need to be electrically connected with each other. However, in the case that the electric motor and the electronic control box are electrically connected by lead wires wired out of the housing, size and weight of the apparatus are increased. Further, in this case, since the lead wires need to be connected to the electric motor and the electronic control box by watertight connectors, cost of the apparatus is increased.
In order to solve this problem, various types of brake fluid control apparatuses are provided. In such apparatuses, through bores elongated from one side to the other side of a housing are formed. An electric motor and an electronic control box are connected with each other by conductive members inserted in the through bores.
For example, in a brake fluid pressure control apparatus for vehicles disclosed in Japanese National Publication No.7-500068 which is the translated version of PCT application PCT/DE92/00738, pipes are inserted in bores, which are formed in a housing and elongated from one side to the other side of the housing. Inside each of the pipes, two lead wires extending from an electric motor and an electronic control box are connected with each other by means of plug.
Further, in a brake fluid pressure control apparatus for vehicles disclosed in Germany Patent DE4320005A1, lead wires elongated from a brash base of an electric motor are inserted in through bores formed in a housing for connection to an electronic control box by means of connector.
However, as above mentioned lead wires have flexibility, operation for connection of the wires need to be executed after finishing operation for inserting the lead wires through the through bores. Further due to the same reason, in order to execute the operation for connection, the length of the lead wires is set so that each of them has an extra portion, and space for accommodating the extra portion is necessary. This results in increase of size of the apparatus. Additionally, in the apparatus disclosed in the Japanese National Publication No.7-500068, since the lead wires extending from the electric motor are pulled out from a motor body, it needs that the motor body is provided with a portion for pulling out the lead wires and the connection of lead wires with the pipes is watertight structure, resulting in cost increasing.
On the other hand, in a brake fluid pressure control apparatus for vehicles disclosed in Japanese Laid-Open Publication No.8-11691, shaft-like conductive members connected to an electric motor are inserted in through bores formed in a housing, and the conductive members are connected to another conductive members in an electronic control box by means of welding or cramping. However, in this apparatus, since the electric motor and the electronic control box are firmly fixed to each other, replacement of the electric motor and the electronic control is difficult after finishing assembly of the apparatus.
In above-mentioned Germany Patent DE4320005A1, a brake fluid pressure control apparatus as shown in FIG. 9 is disclosed. In this apparatus, an opening 2a of the case 2 abutting on a housing 3 is closed by a cover 5 made of insulation plastic having a tubular portion 5a inserted in a through bore 3a of the housing 3. In the tubular potion 5a, a conductive member 7 is inserted. The conductive member 7 has a base end connected to a rectifier 6 and a tip end constituting a male terminal 7a. The male terminal 7a is engaged and connected with a female terminal 9 in an electronic control box 8. In this construction, since the male terminal 7a and the female terminal 9 are connected in releasable manner, even assembly of the apparatus is finished, the electric motor 1 and the electronic control box 8 can be released from the housing 3 for replacement.
Same construction is also disclosed in Japanese Laid-Open Publication No. 9-98559.
However, in such a construction as that the brake fluid control apparatus has the male terminal 7a of the electric motor 7 and the female terminal 9 of the electronic control box 8 shown in FIG. 9, there are still following problems.
As shown in FIG. 10, terminals 12 of devices such as an electromagnetic valve are inserted in through holes 11a of a control circuit substrate 11 accommodated in an electronic control box 8 and soldered to it. Similarly, a male terminal 13b formed at one end of a conductive member 13 having a female terminal 13a (corresponding to the female terminal 9 in FIG. 9) at the other end thereof is inserted in the through hole 11a and welded to the control circuit substrate 11. The female terminal 13a is inserted in a terminal accommodation aperture 8b formed in a terminal accommodation portion 8a of the electronic control box 8. Since the thickness of the female terminal 13a is larger than that of the male terminal 13b, insertion direction of the female terminal 13a to the terminal accommodation aperture 8b (indicated by an arrow "A2") is opposed to a direction in which the male terminal 7a of the electric motor is plugged into the female terminal 7b (indicated by an arrow "A1"). The male terminal 7a is held in the terminal accommodation aperture 8b by engagement of an engagement flap 13c and a step portion 3c of the terminal accommodation aperture 8b. Accordingly, the width "D1" of the terminal accommodation aperture 8b at a portion 8d opposing to the control circuit substrate 11 should be set large for insertion of the female terminal 13a to the terminal accommodation aperture 8b. However, the large width "D1" results in that looseness of the female terminal 13a in a direction indicated by an arrow "B1" is increased and that position of the male terminal 13b with respect to the electronic control box 8 is not determined firmly. When the control circuit substrate 11 is assembled to the electronic control box 8, the terminals 12 of the electromagnetic valves and the male terminal 13b of the conductive member 13 should be simultaneously inserted in the through holes 11a. Therefor, unstable position of the male terminal 13b makes the assembly of the control circuit substrate 11 to the electronic control box 8 considerably difficult.
On the other hand, as shown in FIG. 11, the width "D1" of the terminal accommodation aperture 8b at the portion 8d opposing to the control circuit substrate 11 can be set small. In this case, the female terminal 13a of the conductive member 13 is inserted in the terminal accommodation aperture 8b in the direction as same as the insertion direction of the male terminal 7a indicated by the arrow "A1". However, in this case, the female terminal 13a is almost entirely fixed to the terminal accommodating aperture 8b, so that the female terminal 13a hardly moves in the direction indicated by the arrow "B1". Therefor, in this case, engagement of the male terminal 7a of the electric motor with the female terminal 13a is considerably difficult.
Further, as shown in FIG. 12, in order to decrease the size of the electronic control box 8, a connector portion 8e for connection to a battery (not shown) provided with the electronic control box 8 is formed so that a corresponding connector 15 can be plugged into it in the same direction as the insertion direction of the male terminal 7a of the electronic control box 8 indicated by the arrow "A1".
However, in the case that the female terminal 13a of the conductive member 13 is inserted in the direction of the arrow "A1", insertion direction of the female terminal 13a is opposing to the insertion direction of the terminal 16a of the connector portion 8e indicated by the arrow "A2". Therefor, the female terminal 13a and the terminal 16a can not be formed integrally as one conductive member. Namely, it is necessary that the terminal 16a is formed at one end of a conductive member and a terminal 16b is formed at the other end thereof. Further, the terminal 16b is connected with the male terminal 13b of the conductive member 13 by means of welding or soldering. This necessity for connecting the male terminal 13b and the terminal 16b increases cost and considerably decreases reliability.